The following instructions were written for Adobe InDesign on a Mac. Instructions for Adobe InDesign on Windows should be almost identical.
Save Your Finished Poster as a PDF:
1. First ensure that the document is properly sized for plotter printing. Do this when you first create your new project. Click File > New > Document.
2. You have a number of options that can be set here. Most importantly, under Page Size, choose the correct preset or type the values for width and height. At least one dimension must be 41.5’’ or less. Create your project.
3. You can always return to and modify these settings later. To do so, click File > Document Setup.
4. Once you are finished with your poster, choose File from the toolbar and select "Export."
5. Underneath Format, make sure to select the "Adobe PDF (Print)" option.
6. In the "Save As" box, type in the name of your poster. (Enter your full name in the file, please.)
7. Click "Save." Another dialog box will open; no changes are needed here. Click "Export." Once you have saved the PDF, open the PDF and make sure it looks ok.